US6541786B1 - Plasma pinch high energy with debris collector - Google Patents

Plasma pinch high energy with debris collector Download PDF

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US6541786B1
US6541786B1 US09324526 US32452699A US6541786B1 US 6541786 B1 US6541786 B1 US 6541786B1 US 09324526 US09324526 US 09324526 US 32452699 A US32452699 A US 32452699A US 6541786 B1 US6541786 B1 US 6541786B1
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high energy
source
radiation
photon source
energy photon
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William N. Partlo
Igor V. Fomenkov
Daniel L. Birx
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Cymer Inc
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Cymer Inc
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    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05GX-RAY TECHNIQUE
    • H05G2/00Apparatus or processes specially adapted for producing X-rays, not involving X-ray tubes, e.g. involving generation of a plasma
    • H05G2/001X-ray radiation generated from plasma
    • H05G2/003X-ray radiation generated from plasma being produced from a liquid or gas
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70Exposure apparatus for microlithography
    • G03F7/70008Production of exposure light, i.e. light sources
    • G03F7/70033Production of exposure light, i.e. light sources by plasma EUV sources
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70Exposure apparatus for microlithography
    • G03F7/70058Mask illumination systems
    • G03F7/7015Details of optical elements
    • G03F7/70166Capillary or channel elements, e.g. nested EUV mirrors
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY
    • G03FPHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70Exposure apparatus for microlithography
    • G03F7/708Construction of apparatus, e.g. environment, hygiene aspects or materials
    • G03F7/70908Hygiene, e.g. preventing apparatus pollution, mitigating effect of pollution, removing pollutants from apparatus; electromagnetic and electrostatic-charge pollution
    • G03F7/70916Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05GX-RAY TECHNIQUE
    • H05G2/00Apparatus or processes specially adapted for producing X-rays, not involving X-ray tubes, e.g. involving generation of a plasma
    • H05G2/001X-ray radiation generated from plasma
    • H05G2/003X-ray radiation generated from plasma being produced from a liquid or gas
    • H05G2/005X-ray radiation generated from plasma being produced from a liquid or gas containing a metal as principal radiation generating component
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05HPLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00Generating plasma; Handling plasma
    • H05H1/02Arrangements for confining plasma by electric or magnetic fields; Arrangements for heating plasma
    • H05H1/04Arrangements for confining plasma by electric or magnetic fields; Arrangements for heating plasma using magnetic fields substantially generated by the discharge in the plasma
    • H05H1/06Longitudinal pinch devices

Abstract

A high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber. A working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at voltages high enough to create electrical discharge between the electrodes to produce very high temperature, high density plasma pinch in the working gas providing radiation at the spectral line of the active gas. An external reflection radiation collector-director collects radiation produced in the plasma pinches and directs the radiation in a desired direction. In a preferred embodiment the active gas is lithium and the buffer gas is helium and the radiation collector-director is coated with the material used for the electrodes. A good choice for the material is tungsten. In a second preferred embodiment the buffer gas is argon and lithium gas is produced by vaporization of solid or liquid lithium located in a hole along the axis of the central electrode of a coaxial electrode configuration. Other preferred embodiments utilize a conical nested debris collector upstream of the radiation collector-director.

Description

This application is a continuation-in-part of U.S. Ser. No. 09/268,243 filed Mar. 15, 1999 and U.S. Ser. No. 09/093,416, filed Jun. 8, 1998 which was a CIP of Ser. No. 08/854,507 filed May 12, 1997 which is now U.S. Pat. No. 5,763,930. This invention relates to high energy photon sources and in particular highly reliable x-ray and high energy ultraviolet sources.

BACKGROUND OF THE INVENTION

The semiconductor industry continues to develop lithographic technologies which can print ever smaller integrated circuit dimensions. These systems must have high reliability, cost effective throughput, and reasonable process latitude. The integrated circuit fabrication industry is presently changing over from mercury G-line (436 nm) and I-line (365 nm) exposure sources to 248 nm and 193 nm excimer laser sources. This transition was precipitated by the need for higher lithographic resolution with minimum loss in depth-of-focus.

The demands of the integrated circuit industry will soon exceed the resolution capabilities of 193 nm exposure sources, thus creating a need for a reliable exposure source at a wavelength significantly shorter than 193 nm. An excimer line exists at 157 nm, but optical materials with sufficient transmission at this wavelength and sufficiently high optical quality are difficult to obtain. Therefore, all-reflective imaging systems may be required. An all reflective optical system requires a smaller numerical aperture than the transmissive systems. The loss in resolution caused by the smaller NA can only be made up by reducing the wavelength by a large factor. Thus, a light source in the range of 10 nm is required if the resolution of optical lithography is to be improved beyond that achieved with 193 nm or 157 nm.

The present state of the art in high energy ultraviolet and x-ray sources utilizes plasmas produced by bombarding various target materials with laser beams, electrons or other particles. Solid targets have been used, but the debris created by ablation of the solid target has detrimental effects on various components of a system intended for production line operation. A proposed solution to the debris problem is to use a frozen liquid or frozen gas target so that the debris will not plate out onto the optical equipment. However, none of these systems have proven to be practical for production line operation.

It has been well known for many years that x-rays and high energy ultraviolet radiation could be produced in a plasma pinch operation. In a plasma pinch an electric current is passed through a plasma in one of several possible configuration such that the magnetic field created by the flowing electric current accelerates the electrons and ions in the plasma into a tiny volume with sufficient energy to cause substantial stripping of outer electrons from the ions and a consequent production of x-rays and high energy ultraviolet radiation. Various prior art techniques for generation of high energy radiation from focusing or pinching plasmas are described in the following patents:

J. M. Dawson, “X-Ray Generator,” U.S. Pat. No. 3,961,197, Jun. 1, 1976.

T. G. Roberts, et. al., “Intense, Energetic Electron Beam Assisted X-Ray Generator,” U.S. Pat. No. 3,969,628, Jul. 13, 1976.

J. H. Lee, “Hypocycloidal Pinch Device,” U.S. Pat. No. 4,042,848, Aug. 16, 1977.

L. Cartz, et. al., “Laser Beam Plasma Pinch X-Ray System,” U.S. Pat. No. 4,504,964, Mar. 12, 1985.

A. Weiss, et. al., “Plasma Pinch X-Ray Apparatus,” U.S. Pat. No. 4,536,884, Aug. 20, 1985.

S. Iwamatsu, “X-Ray Source,” U.S. Pat. No. 4,538,291, Aug. 27, 1985.

A. Weiss, et. al, “X-Ray Lithography System,” U.S. Pat. No. 4,618,971, Oct. 21, 1986.

A. Weiss, et. al., “Plasma Pinch X-ray Method,” U.S. Pat. No. 4,633,492, Dec. 30, 1986.

I. Okada, Y. Saitoh, “X-Ray Source and X-Ray Lithography Method,” U.S. Pat. No. 4,635,282, Jan. 6, 1987.

R. P. Gupta, et. al., “Multiple Vacuum Arc Derived Plasma Pinch X-Ray Source,” U.S. Pat. No. 4,751,723, Jun. 14, 1988.

R. P. Gupta, et. al., “Gas Discharge Derived Annular Plasma Pinch X-Ray Source,” U.S. Pat. No. 4,752,946, Jun. 21, 1988.

J. C. Riordan, J. S. Peariman, “Filter Apparatus for use with an X-Ray Source,” U.S. Pat. No. 4,837,794, Jun. 6, 1989.

D. A. Hammer, D. H. Kalantar, “Method and Apparatus for Microlithography Using X-Pinch X-Ray Source,” U.S. Pat. No. 5,102,776, Apr. 7, 1992.

M. W. McGeoch, “Plasma X-Ray Source,” U.S. Pat. No. 5,504,795, Apr. 2, 1996.

Typical prior art plasma focus devices can generate large amounts of radiation suitable for proximity x-ray lithography, but are limited in repetition rate due to large per pulse electrical energy requirements, and short lived internal components. The stored electrical energy requirements for these systems range from 1 kJ to 100 kJ. The repetition rates typically did not exceed a few pulses per second.

What is needed is a production line reliable, simple system for producing high energy ultraviolet and x-radiation which operates at high repetition rates and avoids prior art problems associated with debris formation.

SUMMARY OF THE INVENTION

The present invention provides a high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber. The chamber contains a working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at voltages high enough to create electrical discharges between the electrodes to produce very high temperature, high density plasma pinches in the working gas providing radiation at the spectral line of the active gas. An external reflection radiation collector-director collects radiation produced in the plasma pinches and directs the radiation in a desired direction. In a preferred embodiment the active gas is lithium vapor and the buffer gas is helium and the radiation-collector is made of or coated with a material possessing high grazing incidence reflectivity. Good choices for the reflector material are molybdenum, palladium, ruthenium, rhodium, gold or tungsten.

In other preferred embodiments the buffer gas is argon and lithium gas is produced by vaporization of solid or liquid lithium located in a hole along the axis of the central electrode of a coaxial electrode configuration. In preferred embodiments, debris is collected on a conical nested debris collector having surfaces aligned with light rays extending out from the pinch site and directed toward the radiation collector-director. The conical nested debris collector and the radiation collector-director are maintained at a temperature in the range of about 400° C. which is above the melting point of lithium and substantially below the melting point of tungsten. Both tungsten and lithium vapor will collect on the debris collector but the lithium will evaporate off the debris collector and the collector-director whereas the tungsten will remain permanently on the debris collector and therefore does not collect on and degrade the reflectivity of the radiation collector-director. The reflection radiation collector-director and the conical nested debris collector could be fabricated together as one part or they could be separate parts aligned with each other and the pinch site.

In a preferred embodiment, a unique chamber window is provided designed to transmit EUV light and reflect lower energy light including visible light. This window is preferably a small diameter window comprised of extremely thin material such as silicon or beryllium mounted so as to provide a grazing incident angle incoming beam of about 10°.

Applicants describe a Dense Plasma Focus (DPF) prototype device constructed by Applicants and their fellow workers as a source for extreme ultraviolet (EUV) lithography employing an all-solid-state pulse power drive. Using the results from a vacuum grating spectrometer combined with measurements with a silicon photo diode, Applicants have found that substantial amounts of radiation within the reflectance band of Mo/Si mirrors can be generated using the 13.5 nm emission line of doubly ionized Lithium. This prototype DPF converts 25 J of stored electrical energy per pulse into approximately 0.76 J of in-band 13.5 nm radiation emitted into 4π steradians. The pulse repetition rate performance of this device has been investigated up to its DC power supply limit of 200 Hz. No significant reduction in EUV output per pulse was found up to this repetition rate. At 200 Hz, the measured pulse-to-pulse energy stability was σ=6% and no drop out pulses were observed. The electrical circuit and operation of this prototype DPF device is presented along with a description of several preferred modifications intended to improve stability, efficiency and performance.

The present invention provides a practical implementation of EUV lithography in a reliable, high brightness EUV light source with emission characteristics well matched to the reflection band of the Mo/Si or Mo/Be mirror systems. Since the proposed all-reflective EUV lithography tools are slit scanning based systems, the present invention provides EUV light source with high repetition rate capability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing of a high energy photon source representing a preferred embodiment of the present invention.

FIG. 2 is a drawing of a three dimensional plasma pinch device with disk shaped electrodes.

FIG. 3 is a drawing of a third preferred embodiment of the present invention.

FIG. 4 is a preferred circuit diagram for a preferred embodiment of the present invention.

FIG. 5 is a drawing of a prototype unit built by Applicants and their fellow workers.

FIG. 6 is a pulse shape produced by the prototype unit.

FIG. 7. shows a portion of the EUV beam produced by a hyprobolic collector.

FIG. 8 shows the 13.5 nm lithium peak relative to reflectivity of MoSi coatings.

FIG. 9 shows a nested conical debris collector.

FIG. 10 shows thin Be window for reflecting visible light and transmitting EUV light.

FIG. 11 is a chart showing reflectivity of various materials for 13.5 mn ultraviolet radiation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First Preferred Embodiment

A simplified drawing of a high energy ultraviolet light source is shown in FIG. 1. The major components are a plasma pinch unit 2, a high energy photon collector 4 and a hollow light pipe 6. The plasma pinch source comprises a coaxial electrode 8 powered by a low inductance pulse power circuit 10. The pulse power circuit in this preferred embodiment is a high voltage, energy efficient circuit capable of providing about 5 micro seconds pulses in the range of 1 kV to 2 kV to coaxial electrode 8 at a rate of 1,000 Hz.

A small amount of working gas, such as a mixture of helium and lithium vapor, is present near the base of the electrode 8 as shown in FIG. 1. At each high voltage pulse, avalanche breakdown occurs between the inner and outer electrodes of coaxial electrode 8 either due to preionization or self breakdown. The avalanche process occurring in the buffer gas ionizes the gas and creates a conducting plasma between the electrodes at the base of the electrodes. Once a conducting plasma exists, current flows between the inner and outer electrodes. In this preferred embodiment, the inner electrode is at high positive voltage and outer electrode is at ground potential. Current will flow from the inner electrode to the outer electrode and thus electrons will flow toward the center and positive ions will flow away from the center. This current flow generates a magnetic field which acts upon the moving charge carriers accelerating them away from the base of the coaxial electrode 8.

When the plasma reaches the end of the center electrode, the electrical and magnetic forces on the plasma, pinch the plasma to a “focus” around a point 10 along the centerline of and a short distance from the end of the central electrode and the pressure and temperature of the plasma rise rapidly reaching extremely high temperatures, in come cases much higher than the temperature at the surface of the sun! The dimensions of the electrodes and the total electrical energy in the circuit are preferably optimized to produce the desired black body temperature in the plasma. For the production of radiation in the 13 nm range a black body temperature of about 100 eV is required. In general, for a particular coaxial configuration, temperature will increase with increasing voltage of the electrical pulse. The shape of the radiation spot is somewhat irregular in the axial direction and roughly gausian in the radial direction. The typical radial dimension of the source is 100-300 microns and its length is approximately 4 mm.

In most prior art plasma pinch units described in the technical literature, the radiation spot emits radiation in all directions with a spectrum closely approximating a black body. The purpose of the lithium in the working gas is to narrow the spectrum of the radiation from the radiation spot.

Lithium Vapor

Doubly ionized lithium exhibits an electronic transition at 13.5 nm and serves as the radiation source atom in the buffer of helium. Doubly ionized lithium is an excellent choice for two reasons. The first is the low melting point and high vapor pressure of lithium. The lithium ejected from the radiation spot can be kept from plating out onto the chamber walls and collection optics by simply heating these surfaces above 180° C. The vapor phase lithium can then be pumped from the chamber along with the helium buffer gas using standard turbo-molecular pumping technology. And the lithium can be easily separated from the helium merely by cooling the two gases.

Coating materials are available for providing good reflection at 13.5 nm. FIG. 8 shows the lithium peak in relation to the published MoSi reflectivity.

A third advantage of using lithium as the source atom is that non-ionized lithium has a low absorption cross section for 13.5 nm radiation. Furthermore, any ionized lithium ejected from the radiation spot can be easily swept away with a moderate electric field. The remaining non-ionized lithium is substantially transparent to 13.5 nm radiation. The currently most popular proposed source in the range of 13 nm makes use of a laser ablated frozen jet of xenon. Such a system must capture virtually all of the ejected xenon before the next pulse because the absorption cross section for xenon at 13 nm is large.

Radiation Collector

The radiation produced at the radiation spot is emitted uniformly into a full 4π steradians. Some type of collection optics is needed to capture this radiation and direct it toward the lithography tool. Previously proposed 13 nm light sources suggested collection optics based on the use of multi-layer dielectric coated mirrors. The use of multi-layer dielectric mirrors is used to achieve high collection efficiency over a large angular range. Any radiation source which produced debris would coat these dielectric mirrors and degrade their reflectivity, and thus reduce the collected output from the source. This preferred system will suffer from electrode erosion and thus would, over time, degrade any dielectric mirror placed in proximity to the radiation spot. Several materials are available with high reflectivity at small grazing incident angles for 13.5 nm UV light. Graphs for some of these are shown in FIG. 11. Good choices include molybdenum, rhodium and tungsten. The collector may be fabricated from these materials, but preferably they are applied as a coating on a substrate structural material such as nickel. This conic section can be prepared by electroplating nickel on a removable mandrel.

To produce a collector capable of accepting a large cone angle, several conical sections can be nested inside each other. Each conical section may employ more than one reflection of the radiation to redirect its section of the radiation cone in the desired direction. Designing the collection for operation nearest to grazing incidence will produce a collector most tolerant to deposition of eroded electrode material. The grazing incidence reflectivity of mirrors such as this depends strongly on the mirror's surface roughness. The dependence on surface roughness decreases as the incident angle approaches grazing incidence. We estimate that we can collect and direct the 13 nm radiation being emitted over a solid angle of least 25 degrees. Preferred collectors for directing radiation into light pipes are shown in FIGS. 1, 2 and 3.

Tungsten Electrodes—Tungsten Coatings for Collector

A preferred method for choosing the material for the external reflection collector is that the coating material on the collector be the same as the electrode material. Tungsten is a promising candidate since it has demonstrated performance as an electrode and the real part of its refractive index at 13 nm is 0.945. Using the same material for the electrode and the mirror coating minimizes the degradation of mirror reflectivity as the eroded electrode material plates out onto the collection mirrors.

Silver Electrodes and Coatings

Silver is also an excellent choice for the electrodes and the coatings because it also has a low refractive index at 13 nm and has high thermal conductivity allowing higher repetition rate operation.

Conical Nested Debris Collector

In another preferred embodiment the collector-director is protected from surface contamination with vaporized electrode material by a debris collector which collects all of the tungsten vapor before it can reach the collector director 5. FIG. 9 shows a conical nested debris collector 5 for collecting debris resulting from the plasma pinch. Debris collector 5 is comprised of nested conical sections having surfaces aligned with light rays extending out from the center of the pinch site and directed toward the collector-director 4.

The debris collected includes vaporized tungsten from the tungsten electrodes and vaporized lithium. The debris collector is attached to or is a part of radiation collector-director 4. Both collectors are comprised of nickel plated substrates. The radiation collector-director portion 4 is coated with molybdenum or rhodium for very high reflectivity. Preferably both collectors are heated to about 400° C. which is substantially above the melting point of lithium and substantially below the melting point of tungsten. The vapors of both lithium and tungsten will collect on the surfaces of the debris collector 5 but lithium will vaporize off and to the extent the lithium collects on collector-director 4, it will soon thereafter also vaporize off. The tungsten once collected on debris collector 5 will remain there permanently.

FIG. 7 shows the optical features of a collector designed by Applicants. The collector is comprised of five nested grazing incident parabolic reflectors, but only three of the five reflections are shown in the drawing. The two inner reflectors are not shown. In this design the collection angle is about 0.4 steradians. As discussed below the collector surface is coated and is heated to prevent deposition of lithium. This design produces a parallel beam. Other preferred designs such as that shown in FIGS. 1, 3 and 10 would focus the beam. The collector should be coated with a material possessing high glazing incidence reflectivity in the 13.5 nm wavelength range. Two such materials are palladium and ruthenium.

Light Pipe

It is important to keep deposition materials away from the illumination optics of the lithography tool. Therefore, a light pipe 6 is preferred to further assure this separation. The lightpipe 6 is a hollow lightpipe which also employs substantially total external reflection on its inside surfaces. The primary collection optic can be designed to reduce the cone angle of the collected radiation to match the acceptance angle of the hollow lightpipe. This concept is shown in FIG. 1.

The dielectric mirrors of the lithography tool would then be very well protected from any electrode debris since a tungsten, silver or lithium atom would have to diffuse upstream against a flow of buffer gas down the hollow lightpipe as shown in FIG. 1.

Pulse Power Unit

The preferred pulse power unit 10 is a solid state high frequency, high voltage pulse power unit utilizing a solid state trigger and a magnetic switch circuit such as the pulse power units described in U.S. Pat. No. 5,142,166. These units are extremely reliable and can operate continuously without substantial maintenance for many months and billions of pulses. The teachings of U.S. Pat. No. 5,142,166 are incorporated herein by reference.

FIG. 4 shows a simplified electrical circuit providing pulse power. A preferred embodiment includes DC power supply 40 which is a command resonant charging supply of the type used in excimer lasers. C0 which is a bank of off the shelf capacitors having a combined capacitance of 65 μF, a peaking capacitor C1 which is also a bank of off the shelf capacitors having a combined capacitance of 65 μF. Saturable inductor 42 has a saturated drive inductance of about 1.5 nH. Trigger 44 is an IGBT. Diode 46 and inductor 48 creates an energy recovery circuit similar to that described in U.S. Pat. No. 5,729,562 permitting reflected electrical energy from one pulse to be stored on C0 prior to the next pulse.

The System—First Preferred Embodiment

Thus, as shown in FIG. 1, in a first preferred embodiment, a working gas mixture of helium and lithium vapor is discharged into coaxial electrode 8. Electrical pulses from pulse power unit 10 create a dense plasma focus at 11 at sufficiently high temperatures and pressures to doubly ionize the lithium atoms in the working gas generating ultraviolet radiation at about 13.5 nm wavelength.

This light is collected in total external reflection-collector 4 and directed into hollow light pipe 6 where the light is further directed to a lithography tool (not shown). Discharge chamber 1 is maintained at a vacuum of about 4 Torr with turbo suction pump 12. Some of the helium in the working gas is separated in helium separator 14 and used to purge the lightpipe as shown in FIG. 1 at 16. The pressure of helium in the light pipe is preferably matched to the pressure requirements of the lithography tool which typically is maintained at a low pressure or vacuum. The temperature of the working gas is maintained at the desired temperature with heat exchanger 20 and the gas is cleaned with electrostatic filter 22. The gas is discharged into the coaxial electrode space as shown in FIG. 1.

Prototype Unit

A drawing of a prototype plasma pinch unit built and tested by Applicant and his fellow workers is shown in FIG. 5. Principal elements are C1 capacitor decks, C0 capacitor decks 1 GBT switches, saturable inductor 42, vacuum vessel 3, and coaxial electrode 8.

Test Results

FIG. 6 shows a typical pulse shape measured by Applicant with the unit shown in FIG. 5. Applicants have recorded C1 voltage, C1 current and intensity at 13.5 nm over an 8 microsecond period. The integrated energy in this typical pulse is about 0.8 J. The pulse width (at FWHM) is about 280 ns. The C1 voltage prior to breakdown is a little less than 1 KV.

This prototype embodiment can be operated at a pulse rate up to 200 Hz. The measured average in-band 13.5 nm radiation at 200 Hz is 152 W in 4π steradians. Energy stability at 1 sigma is about 6%. Applicants estimate that 3.2 percent of the energy can be directed into a useful 13.5 nm beam with the collector 4 shown in FIG. 1.

Second Preferred Plasma Pinch Unit

A second preferred plasma pinch unit is shown in FIG. 2. This unit is similar to the plasma pinch device described in U.S. Pat. No. 4,042,848. This unit comprises two outer disk shaped electrodes 30 and 32 and an inner disk shaped electrode 36. The pinch is created from three directions as described in U.S. Pat. No. 4,042,848 and as indicated in FIG. 2. The pinch starts near the circumference of the electrodes and proceeds toward the center and the radiation spot is developed along the axis of symmetry and at the center of the inner electrode as shown in FIG. 2 at 34. Radiation can be collected and directed as described with respect to the FIG. 1 embodiment. However, it is possible to capture radiation in two directions coming out of both sides of the unit as shown in FIG. 2. Also, by locating a dielectric mirror at 38, a substantial percentage of the radiation initially reflected to the left could be reflected back through the radiation spot. This should stimulate radiation toward the right side.

Third Preferred Embodiment

A third preferred embodiment can be described by reference to FIG. 3. This embodiment is similar to the first preferred embodiment. In this embodiment, however, the buffer gas is argon. Helium has the desirable property that it is relatively transparent to 13 nm radiation, but it has the undesired property that it has a small atomic mass. The low atomic mass forces us to operate the system at a background pressure of 2-4 Torr. An additional drawback of the small atomic mass of He is the length of electrode required to match the acceleration distance with the timing of the electrical drive circuit. Because He is light, the electrode must be longer than desired so that the He falls off the end of the electrode simultaneous with the peak of current flow through the drive circuit.

A heavier atom such as Ar will have a lower transmission than He for a given pressure, but because of its higher mass can produce a stable pinch at a lower pressure. The lower operating pressure of Ar more than offsets the increased absorption properties of Ar. Additionally, the length of the electrode required is reduced due to the higher atomic mass. A shorter electrode is advantageous for two reasons. The first is a resulting reduction in circuit inductance when using a shorter electrode. A lower inductance makes the drive circuit more efficient and thus reduces the required electrical pump energy. The second advantage of a shorter electrode is a reduction in the thermal conduction path length from the tip of the electrode to the base. The majority of the thermal energy imparted to the electrode occurs at the tip and the conductive cooling of the electrode occurs mainly at the base (radiative cooling also occurs). A shorter electrode leads to a smaller temperature drop down its length from the hot tip to the cool base. Both the smaller pump energy per pulse and the improved cooling path allow the system to operate at a higher repetition rate. Increasing the repetition rate directly increases the average optical output power of the system. Scaling the output power by increasing repetition rate, as opposed to increasing the energy per pulse, is the most desired method for the average output power of lithography light sources.

In this preferred embodiment the lithium is not injected into the chamber in gaseous form as in the first and second embodiments. Instead solid lithium is placed in a hole in the center of the central electrode as shown in FIG. 3. The heat from the electrode then brings the lithium up to its evaporation temperature. By adjusting the height of the lithium relative to the hot tip of the electrode one can control the partial pressure of lithium near the tip of the electrode. One preferred method of doing this is shown in FIG. 3. A mechanism is provided for adjusting the tip of the solid lithium rod relative to the tip of the electrode. Preferably the system is arranged vertically so that the open side of coaxial electrodes 8 is the top so that any melted lithium will merely puddle near the top of the center electrode. The beam will exit straight up in a vertical direction as indicated in FIG. 5. (An alternative approach is to heat the electrode to a temperature in excess of the lithium melting point so that the lithium is added as a liquid.)

The hole down the center of the electrode provides another important advantage. Since the plasma pinch forms near the center of the tip of the central electrode, much of the energy is dissipated in this region. Electrode material near this point will be ablated and eventually end up of other surfaces inside the pressure vessel. Employing an electrode with a central hole greatly reduces the available erosion material. In addition, Applicant's experiments have shown that the existence of lithium vapor in this region further reduces the erosion rate of electrode material. A bellows or other appropriate sealing method should be used to maintain a good seal where the electrode equipment enters the chamber. Replacement electrodes fully loaded with the solid lithium can be easily and cheaply manufactured and easily replaced in the chamber.

Small Vacuum Chamber Window

The pinch produces a very large amount of viable light which needs to be separated from the EUV light. Also, a window is desirable to provide additional assurance that lithography optics are not contaminated with lithium or tungsten. The extreme ultraviolet beam produced by the present invention is highly absorbed in solid matter. Therefore providing a window for the beam is a challenge. Applicants preferred window solution is to utilize an extremely thin foil which will transmit EUV and reflect visible. Applicants preferred window is a foil (about 0.2 to 0.5 micron) of beryllium tilted at an incident angle of about 10° C. with the axis of the incoming beam. With this arrangement, almost all of the visible light is reflected and about 50 to 80 percent of the EUV is transmitted. Such a thin window, of course, is not very strong. Therefore, Applicants use a very small diameter window and the beam is focused through the small window. Preferably the diameter of the thin beryllium window is about 1.0 mm. Heating of the little window must be considered, and for high repetition rates special cooling of the window will be needed.

In some designs this element can be designed merely as a beam splitter which will simplify the design since there will be no pressure differential across the thin optical element.

FIG. 10 shows a preferred embodiment in which radiation collector 4 is extended by collector extension 4A to focus the beam 9 through 0.5 micron thick 1 mm diameter beryllium window 7.

Preionization

Applicants experiments have shown that good results can be obtained without preionization but performance is improved with preionization. The prototype unit shown in FIG. 5 comprises DC driven spark gap preionizers to preionize the gas between the electrodes. Applicants will be able to greatly improve these energy stability values and improve other performance parameters with improved preionization techniques. Preionization is a well developed technique used by Applicants and others to improve performance in excimer lasers. Preferred preionization techniques include:

1) DC drive spark gap

2) RF driven spark gap

3) RF driven surface discharge

4) Corona discharge

5) Spiker circuit in combination with preionization

These techniques are well described in scientific literature relating to excimer lasers and are well known.

It is understood that the above described embodiments are illustrative of only a few of the many possible specific embodiments which can represent applications of the principals of the present invention. For example, instead of recirculating the working gas it may be preferable to merely trap the lithium and discharge the helium. Use of other electrode—coating combinations other than tungsten and silver are also possible. For example copper or platinum electrodes and coatings would be workable. Other techniques for generating the plasma pinch can be substituted for the specific embodiment described. Some of these other techniques are described in the patents referenced in the background section of this specification, and those descriptions are all incorporated by reference herein. Many methods of generating high frequency high voltage electrical pulses are available and can be utilized. An alternative would be to keep the lightpipe at room temperature and thus freeze out both the lithium and the tungsten as it attempts to travel down the length of the lightpipe. This freeze-out concept would further reduce the amount of debris which reached the optical components used in the lithography tool since the atoms would be permanently attached to the lightpipe walls upon impact. Deposition of electrode material onto the lithography tool optics can be prevented by designing the collector optic to re-image the radiation spot through a small orifice in the primary discharge chamber and use a differential pumping arrangement. Helium or argon can be supplied from the second chamber through the orifice into the first chamber. This scheme has been shown to be effective in preventing material deposition on the output windows of copper vapor lasers. Lithium hydride may be used in the place of lithium. The unit may also be operated as a static-fill system without the working gas flowing through the electrodes. Of course, a very wide range of repetition rates are possible from single pulses to about 5 pulses per second to several hundred or thousands of pulses per second. If desired, the adjustment mechanism for adjusting the position of the solid lithium could be modified so that the position of the tip of the central electrode is also adjustable to account for erosion of the tip.

Many other electrode arrangements are possible other than the ones described above. For example, the outside electrode could be cone shaped rather than cylindrical as shown with the larger diameter toward the pinch. Also, performance in some embodiments could be improved by allowing the inside electrode to pertrude beyond the end of the outside electrode. This could be done with spark plugs or other preionizers well known in the art. Another preferred alternative is to utilize for the outer electrode an array of rods arranged to form a generally cylindrical or conical shape. This approach helps maintain a symmetrical pinch centered along the electrode axis because of the resulting inductive ballasting.

Accordingly, the reader is requested to determine the scope of the invention by the appended claims and their legal equivalents; and not by the examples which have been given.

Claims (34)

What is claimed is:
1. A high energy photon source comprising:
A. a vacuum chamber,
B. two electrodes located within said vacuum chamber and defining an electrical discharge region between said two electrodes and arranged to create high frequency plasma pinches focused at a pinch site outside said electrical discharge region upon electrical discharge,
C. a working gas comprising an active gas and a buffer gas, said buffer gas being a noble gas, and said active gas being chosen to provide light at least one spectral line,
D. a working gas supply system for supplying a working gas to said discharge region,
E. a pulse power source for providing electrical pulses and voltages high enough to create electrical discharge between said at least one pair of electrode,
F. an external reflection radiation collector-director for collecting radiation produced in said plasma pinches and for directing said radiation in a desired direction, and
G. a conical nested debris collector having at least five conical surfaces aligned with light rays extending out from the pinch site toward the radiation collector-director;
wherein at least four of said at least five conical surfaces are nested within one of said five conical surfaces.
2. A high energy photon source as in claim 1 wherein said conical nested debris collector is fabricated as a part of said radiation collector-director.
3. A high energy photon source as in claim 1 wherein said active gas is a vapor of a metal defining a melting point and further comprising a heating means to maintain said radiation collector and said debris collector at a temperature in excess of the melting point of said metal.
4. A high energy photon source as in claim 3 wherein said metal is lithium.
5. A high energy photon source as in claim 1 wherein said pulse power source is programmable to provide electrical pulses at frequencies of at least 5 Hz.
6. A high energy photon source as in claim 1 wherein said active gas is produced by heating of a solid material.
7. A high energy photon source as in claim 2 wherein said solid material is solid lithium.
8. A high energy photon source as in claim 3 wherein said solid lithium is located in one of said two electrodes.
9. A high energy photon source as in claim 7 wherein said two electrodes are configured coaxially to define a central electrode defining an axis and a central tip and said solid lithium is positioned along said axis.
10. A high energy photon source as in claim 9 further comprising a position adjustment means to adjust said lithium relative to said central electrode tip.
11. A high energy photon source as in claim 1 wherein said active gas is lithium vapor.
12. A high energy photon source as in claim 1 wherein said active gas is lithium hydride.
13. A high energy photon source as in claim 1 and further comprising a light pipe arranged to transmit radiation collected and directed by said collector-director.
14. A high energy photon source as in claim 1 wherein said electrodes are comprised of an electrode material and said collector-directed is coated with the same electrode material.
15. A high energy photon source as in claim 14 wherein said electrode material is tungsten.
16. A high energy photon source as in claim 14 wherein said electrode material is silver.
17. A high energy photon source as in claim 1 wherein said buffer gas is helium.
18. A high energy photon source as in claim 1 wherein said buffer gas is argon.
19. A high energy photon source as in claim 1 wherein said buffer gas is radon.
20. A high energy photon source as in claim 1 wherein said at least two electrodes are three disk shaped electrodes defining two outer electrodes and an inner electrode, said two inner electrodes during operation being at a polarity opposite said inner electrode.
21. A high energy photon source as in claim 1 wherein said two electrodes are configured coaxially to define a central electrode defining an axis and an outer electrode comprised of an array of rods.
22. A high energy photon source as in claim 21 wherein said array of rods are arranged to form in a generally cylindrical shape.
23. A high energy photon source as in claim 21 wherein said array of rods are arranged to form a generally conical shape.
24. A high energy source as in claim 1 and further comprising a preionizer for preionizing said working gas.
25. A high energy source as in claim 24 wherein said preionizer is a DC spark gap ionizer.
26. A high energy source as in claim 24 wherein said preionizer is a RF driven spark gap.
27. A high energy source as in claim 25 wherein said preionizer is a RF driven surface discharge.
28. A high energy source as in claim 25 wherein said preionizer is a corona discharge.
29. A high energy source as in claim 24 wherein said preionizer comprises a spiker circuit.
30. A high energy source as in claim 1 and further comprising a vacuum chamber window for transmitting extreme ultraviolet radiation and reflecting visible light.
31. A high energy source as in claim 30 wherein said window is comprised of a sheet of a solid material having a thickness of less than 1 micron.
32. A high energy source as in claim 30 wherein said material is chosen from group of materials consisting of beryllium and silicon.
33. A high energy photon source as in claim 30 and further comprising a focusing means for focusing said radiation on to said windows.
34. A high energy source as in claim 1 and further comprising a beam splitter for transmitting extreme ultraviolet radiation and reflecting visible light.
US09324526 1997-05-12 1999-06-02 Plasma pinch high energy with debris collector Expired - Fee Related US6541786B1 (en)

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US08854507 US5763930A (en) 1997-05-12 1997-05-12 Plasma focus high energy photon source
US09093416 US6051841A (en) 1997-05-12 1998-06-08 Plasma focus high energy photon source
US09268243 US6064072A (en) 1997-05-12 1999-03-15 Plasma focus high energy photon source
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US09324526 US6541786B1 (en) 1997-05-12 1999-06-02 Plasma pinch high energy with debris collector
US09442582 US6452199B1 (en) 1997-05-12 1999-11-18 Plasma focus high energy photon source with blast shield
DE2000642354 DE60042354D1 (en) 1999-03-15 2000-03-14 Plasma source of high-energy photons
KR20000012713A KR100319001B1 (en) 1999-03-15 2000-03-14 Plasma focus high energy photon source
KR20000012732A KR100358447B1 (en) 1999-03-15 2000-03-14 Plasma focus high energy photon source with blast shield
EP20000105276 EP1047288B1 (en) 1999-03-15 2000-03-14 Plasma focus high energy photon source
EP20000105278 EP1037510A3 (en) 1999-03-15 2000-03-14 Plasma focus high energy photon source with blast shield
JP2000118725A JP2001042098A (en) 1999-03-15 2000-03-15 Plasma focused high energy photon source
KR20000029912A KR20010007165A (en) 1999-06-02 2000-06-01 Plasma focus high energy photon source
KR20000029940A KR20010029769A (en) 1999-06-02 2000-06-01 Plasma focus high energy photon source with blast shield
US09690084 US6566667B1 (en) 1997-05-12 2000-10-16 Plasma focus light source with improved pulse power system
US09875721 US6566668B2 (en) 1997-05-12 2001-06-06 Plasma focus light source with tandem ellipsoidal mirror units
US09875719 US6586757B2 (en) 1997-05-12 2001-06-06 Plasma focus light source with active and buffer gas control
US10120655 US6744060B2 (en) 1997-05-12 2002-04-10 Pulse power system for extreme ultraviolet and x-ray sources
US10189824 US6815700B2 (en) 1997-05-12 2002-07-03 Plasma focus light source with improved pulse power system

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Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020167986A1 (en) * 2000-11-17 2002-11-14 Xiaojiang Pan Gas discharge ultraviolet laser with enclosed beam path with added oxidizer
US20030006383A1 (en) * 1997-05-12 2003-01-09 Melnychuk Stephan T. Plasma focus light source with improved pulse power system
US20030068012A1 (en) * 2001-10-10 2003-04-10 Xtreme Technologies Gmbh; Arrangement for generating extreme ultraviolet (EUV) radiation based on a gas discharge
US20050111080A1 (en) * 2003-10-20 2005-05-26 Asml Netherlands B.V. Mirror for use in a lithographic apparatus, lithographic apparatus, device manufacturing method, and device manufactured thereby
US20050148210A1 (en) * 2002-08-15 2005-07-07 Asml Netherlands B.V. Lithographic projection apparatus, reflector assembly for use therein, and device manufacturing method
EP1557844A2 (en) * 2003-10-20 2005-07-27 ASML Netherlands B.V. Use of a top layer on a mirror for use in a lithographic apparatus, mirror for use in a lithographic apparatus, lithographic apparatus comprising such a mirror and device manufacturing method
US20050269529A1 (en) * 2004-03-10 2005-12-08 Cymer, Inc. Systems and methods for reducing the influence of plasma-generated debris on the internal components of an EUV light source
US20050279946A1 (en) * 2003-04-08 2005-12-22 Cymer, Inc. Systems and methods for deflecting plasma-generated ions to prevent the ions from reaching an internal component of an EUV light source
US20050286599A1 (en) * 2004-06-29 2005-12-29 Rafac Robert J Method and apparatus for gas discharge laser output light coherency reduction
US20060006345A1 (en) * 2004-07-09 2006-01-12 Energetig Technology Inc. Inductively-driven light source for lithography
US20060006808A1 (en) * 2004-07-09 2006-01-12 Energetiq Technology Inc. Inductively-driven light source for microscopy
US20060006775A1 (en) * 2004-07-09 2006-01-12 Energetiq Technology Inc. Inductively-driven plasma light source
US20060017387A1 (en) * 2004-07-09 2006-01-26 Energetiq Technology Inc. Inductively-driven plasma light source
US20060097203A1 (en) * 2004-11-01 2006-05-11 Cymer, Inc. Systems and methods for cleaning a chamber window of an EUV light source
US20060219957A1 (en) * 2004-11-01 2006-10-05 Cymer, Inc. Laser produced plasma EUV light source
US20060249699A1 (en) * 2004-03-10 2006-11-09 Cymer, Inc. Alternative fuels for EUV light source
US20060289808A1 (en) * 2005-06-27 2006-12-28 Cymer, Inc. Euv light source collector erosion mitigation
US20070075053A1 (en) * 2005-09-30 2007-04-05 Energetiq Technology, Inc. Inductively-driven plasma light source
US7394083B2 (en) 2005-07-08 2008-07-01 Cymer, Inc. Systems and methods for EUV light source metrology
US20080179548A1 (en) * 2003-04-08 2008-07-31 Cymer, Inc. Laser produced plasma EUV light source
US20090027637A1 (en) * 2007-07-23 2009-01-29 Asml Netherlands B.V. Debris prevention system and lithographic apparatus
US20090057567A1 (en) * 2007-08-31 2009-03-05 Cymer, Inc. Gas management system for a laser-produced-plasma EUV light source
US20090154642A1 (en) * 2007-12-14 2009-06-18 Cymer, Inc. System managing gas flow between chambers of an extreme ultraviolet (EUV) photolithography apparatus
US20100032590A1 (en) * 2008-08-06 2010-02-11 Cymer, Inc. Debris protection system having a magnetic field for an EUV light source
US20100176313A1 (en) * 2000-10-16 2010-07-15 Cymer, Inc. Extreme ultraviolet light source
US7856044B2 (en) 1999-05-10 2010-12-21 Cymer, Inc. Extendable electrode for gas discharge laser
US7948185B2 (en) 2004-07-09 2011-05-24 Energetiq Technology Inc. Inductively-driven plasma light source
US20120146511A1 (en) * 2009-09-01 2012-06-14 Ihi Corporation Plasma light source
US20120145930A1 (en) * 2009-09-01 2012-06-14 Tokyo Institute Of Technology Llp euv light source and method for producing the same
US8440988B2 (en) 2010-12-09 2013-05-14 Plex Llc Pulsed discharge extreme ultraviolet source with magnetic shield
US8629417B2 (en) 2010-02-22 2014-01-14 Gigaphoton Inc. Extreme ultraviolet light generation apparatus
US8921814B2 (en) 2012-06-12 2014-12-30 Asml Netherlands B.V. Photon source, metrology apparatus, lithographic system and device manufacturing method

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7217940B2 (en) * 2003-04-08 2007-05-15 Cymer, Inc. Collector for EUV light source
US6630799B2 (en) 2001-03-15 2003-10-07 Safe Food Technologies, Inc. Resonant power supply and apparatus for producing vacuum arc discharges
US6765987B2 (en) * 2001-03-15 2004-07-20 Safe Food Technologies, Inc. Resonant plasma x-ray source
FR2860385B1 (en) * 2003-09-26 2007-06-01 Cit Alcatel EUV source
US7369216B2 (en) * 2004-10-15 2008-05-06 Asml Netherlands B.V. Lithographic system, method for adapting transmission characteristics of an optical pathway within a lithographic system, semiconductor device, method of manufacturing a reflective element for use in a lithographic system, and reflective element manufactured thereby
US7193229B2 (en) * 2004-12-28 2007-03-20 Asml Netherlands B.V. Lithographic apparatus, illumination system and method for mitigating debris particles
DE102005007370B3 (en) * 2005-02-17 2006-09-21 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Ultraviolet light source for e.g. ultraviolet microscopy, has dielectric arranged between two electrodes, where one electrode includes tip directed to another electrode, such that shortest distance is defined between electrodes
US7109503B1 (en) * 2005-02-25 2006-09-19 Cymer, Inc. Systems for protecting internal components of an EUV light source from plasma-generated debris
JP2006294606A (en) * 2005-04-12 2006-10-26 Xtreme Technologies Gmbh Plasma radioactive source
JP4710463B2 (en) * 2005-07-21 2011-06-29 ウシオ電機株式会社 Extreme ultraviolet light generator
WO2008098913A1 (en) * 2007-02-14 2008-08-21 O.C.E.M. S.P.A. An apparatus for activating a plasma focus unit
US7839482B2 (en) * 2007-05-21 2010-11-23 Asml Netherlands B.V. Assembly comprising a radiation source, a reflector and a contaminant barrier
WO2009135163A3 (en) 2008-05-02 2010-02-25 Phoenix Nuclear Labs Llc Device and method for producing medical isotopes
JP5758153B2 (en) 2010-03-12 2015-08-05 エーエスエムエル ネザーランズ ビー.ブイ. The source device, the lithographic apparatus and the radiation generation and delivery methods, and device manufacturing method
JP5474891B2 (en) * 2011-08-12 2014-04-16 ギガフォトン株式会社 A light source apparatus and an exposure apparatus using the same

Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3746870A (en) * 1970-12-21 1973-07-17 Gen Electric Coated light conduit
US3960473A (en) * 1975-02-06 1976-06-01 The Glastic Corporation Die structure for forming a serrated rod
US4042848A (en) 1974-05-17 1977-08-16 Ja Hyun Lee Hypocycloidal pinch device
US4088966A (en) * 1974-06-13 1978-05-09 Samis Michael A Non-equilibrium plasma glow jet
US4162160A (en) * 1977-08-25 1979-07-24 Fansteel Inc. Electrical contact material and method for making the same
US4596030A (en) 1983-09-10 1986-06-17 Carl Zeiss Stiftung Apparatus for generating a source of plasma with high radiation intensity in the X-ray region
US4626193A (en) * 1985-08-02 1986-12-02 Itt Corporation Direct spark ignition system
US4751723A (en) 1985-10-03 1988-06-14 Canadian Patents And Development Ltd. Multiple vacuum arc derived plasma pinch x-ray source
US4752946A (en) 1985-10-03 1988-06-21 Canadian Patents And Development Ltd. Gas discharge derived annular plasma pinch x-ray source
US5023897A (en) 1989-08-17 1991-06-11 Carl-Zeiss-Stiftung Device for generating X-radiation with a plasma source
US5027076A (en) * 1990-01-29 1991-06-25 Ball Corporation Open cage density sensor
US5102776A (en) 1989-11-09 1992-04-07 Cornell Research Foundation, Inc. Method and apparatus for microlithography using x-pinch x-ray source
US5142166A (en) 1991-10-16 1992-08-25 Science Research Laboratory, Inc. High voltage pulsed power source
US5411224A (en) * 1993-04-08 1995-05-02 Dearman; Raymond M. Guard for jet engine
US5499282A (en) * 1994-05-02 1996-03-12 University Of Central Florida Efficient narrow spectral width soft-X-ray discharge sources
US5504795A (en) 1995-02-06 1996-04-02 Plex Corporation Plasma X-ray source
US5729562A (en) * 1995-02-17 1998-03-17 Cymer, Inc. Pulse power generating circuit with energy recovery
US5763930A (en) 1997-05-12 1998-06-09 Cymer, Inc. Plasma focus high energy photon source
US5963616A (en) * 1997-03-11 1999-10-05 University Of Central Florida Configurations, materials and wavelengths for EUV lithium plasma discharge lamps
US6232613B1 (en) * 1997-03-11 2001-05-15 University Of Central Florida Debris blocker/collector and emission enhancer for discharge sources

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3426233A (en) * 1965-12-13 1969-02-04 Vitro Corp Of America Plasma stabilization by rotation of arc discharge tube
US4578805A (en) * 1984-10-10 1986-03-25 Maxwell Laboratories, Inc. Transmission line transmitting energy to load in vacuum chamber
GB2260854B (en) * 1991-10-22 1995-04-05 British Aerospace Surface discharge corona plasma cathode assembly
JP3440735B2 (en) * 1996-12-26 2003-08-25 ソニー株式会社 Dry etching method

Patent Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3746870A (en) * 1970-12-21 1973-07-17 Gen Electric Coated light conduit
US4042848A (en) 1974-05-17 1977-08-16 Ja Hyun Lee Hypocycloidal pinch device
US4088966A (en) * 1974-06-13 1978-05-09 Samis Michael A Non-equilibrium plasma glow jet
US3960473A (en) * 1975-02-06 1976-06-01 The Glastic Corporation Die structure for forming a serrated rod
US4162160A (en) * 1977-08-25 1979-07-24 Fansteel Inc. Electrical contact material and method for making the same
US4596030A (en) 1983-09-10 1986-06-17 Carl Zeiss Stiftung Apparatus for generating a source of plasma with high radiation intensity in the X-ray region
US4626193A (en) * 1985-08-02 1986-12-02 Itt Corporation Direct spark ignition system
US4751723A (en) 1985-10-03 1988-06-14 Canadian Patents And Development Ltd. Multiple vacuum arc derived plasma pinch x-ray source
US4752946A (en) 1985-10-03 1988-06-21 Canadian Patents And Development Ltd. Gas discharge derived annular plasma pinch x-ray source
US5023897A (en) 1989-08-17 1991-06-11 Carl-Zeiss-Stiftung Device for generating X-radiation with a plasma source
US5102776A (en) 1989-11-09 1992-04-07 Cornell Research Foundation, Inc. Method and apparatus for microlithography using x-pinch x-ray source
US5027076A (en) * 1990-01-29 1991-06-25 Ball Corporation Open cage density sensor
US5142166A (en) 1991-10-16 1992-08-25 Science Research Laboratory, Inc. High voltage pulsed power source
US5411224A (en) * 1993-04-08 1995-05-02 Dearman; Raymond M. Guard for jet engine
US5499282A (en) * 1994-05-02 1996-03-12 University Of Central Florida Efficient narrow spectral width soft-X-ray discharge sources
US5504795A (en) 1995-02-06 1996-04-02 Plex Corporation Plasma X-ray source
US5729562A (en) * 1995-02-17 1998-03-17 Cymer, Inc. Pulse power generating circuit with energy recovery
US5963616A (en) * 1997-03-11 1999-10-05 University Of Central Florida Configurations, materials and wavelengths for EUV lithium plasma discharge lamps
US6232613B1 (en) * 1997-03-11 2001-05-15 University Of Central Florida Debris blocker/collector and emission enhancer for discharge sources
US5763930A (en) 1997-05-12 1998-06-09 Cymer, Inc. Plasma focus high energy photon source

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
Bollanti, S., Di Lazzaro, P., Flora, F., Giordano, G., Letardi, T., Schina, G. and Zheng, C.E., "Ianus, the three-electrode excimer laser", Appl. Phys. B 66, 1998, pp. 401-406.
Lebert, R. and Schriever, G., "Soft x-ray emission of laser-produced plasmas using a low-debris cryogenic nitrogen target ", Journal of Applied Physics, vol. 84, No. 6, Sep. 15, 1998, pp. 3419-3421.
Lebert, R., Bergmann, K., Schriever, G. and Neff, W., "Comparison of laser produced and gas discharge based EUV sources for different applications",International Conference Micro- and Nano- Engineering98, Sep. 22-24, 1998, Leuven, Belgium, 6 pages.
Lebert, R., Bergmann, K., Schriever, G., Neff, W., "A gas discharged based radiation source for EUV-lithography", International Conference Micro- and Nano- Engineering98, Sep.22-24, Leuven, Belgium, 5 pages.
Maimqvist, L., Rymell, L., Berglund, M., and Hertz, H.M., "Liquid-jet target for laser-plasma soft x-ray generation",Rev. Sci. Instrum, 67 (12), Dec. 1996, pp. 4150-4153.
Schriever, G., Bergmann and Lebert, R., "Narrowband laser produced extreme ultraviolet sources adapted to silicon/molybdenummultilayer optics", Journal of Applied Physics, vol. 83, No. 9, May 1, 1998, pp. 4566-4571.
Schriever, G., Mager, S., Naweed, A., Engel, A., Bergmann, K. and Lebert, R., "Laser-producedlithium plasma as a narrow-band extended ultraviolet radiation source for photoelectron spectroscopy",Applied Optics, vol. 37, No. 7, Mar. 1, 1998, pp. 1243-1248.

Cited By (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030006383A1 (en) * 1997-05-12 2003-01-09 Melnychuk Stephan T. Plasma focus light source with improved pulse power system
US6815700B2 (en) * 1997-05-12 2004-11-09 Cymer, Inc. Plasma focus light source with improved pulse power system
US7856044B2 (en) 1999-05-10 2010-12-21 Cymer, Inc. Extendable electrode for gas discharge laser
US20100176313A1 (en) * 2000-10-16 2010-07-15 Cymer, Inc. Extreme ultraviolet light source
US6839372B2 (en) 2000-11-17 2005-01-04 Cymer, Inc. Gas discharge ultraviolet laser with enclosed beam path with added oxidizer
US20020167986A1 (en) * 2000-11-17 2002-11-14 Xiaojiang Pan Gas discharge ultraviolet laser with enclosed beam path with added oxidizer
US8526481B2 (en) 2001-01-23 2013-09-03 Cymer, Inc. Extendable electrode for gas discharge laser
US20110058580A1 (en) * 2001-01-23 2011-03-10 Sandstrom Richard L Extendable electrode for gas discharge laser
US8446928B2 (en) 2001-01-23 2013-05-21 Cymer, Inc. Extendable electrode for gas discharge laser
US6894298B2 (en) * 2001-10-10 2005-05-17 Xtreme Technologies Gmbh Arrangement for generating extreme ultraviolet (EUV) radiation based on a gas discharge
US20030068012A1 (en) * 2001-10-10 2003-04-10 Xtreme Technologies Gmbh; Arrangement for generating extreme ultraviolet (EUV) radiation based on a gas discharge
US20050148210A1 (en) * 2002-08-15 2005-07-07 Asml Netherlands B.V. Lithographic projection apparatus, reflector assembly for use therein, and device manufacturing method
US7852460B2 (en) 2002-08-15 2010-12-14 Asml Netherlands B.V. Lithographic projection apparatus, reflector assembly for use therein, and device manufacturing method
US20060250599A1 (en) * 2002-08-15 2006-11-09 Asml Netherlands B.V. Lithographic projection apparatus, reflector assembly for use therein, and device manufacturing method
US7088424B2 (en) * 2002-08-15 2006-08-08 Asml Netherlands B.V. Lithographic projection apparatus, reflector assembly for use therein, and device manufacturing method
US20100127186A1 (en) * 2003-04-08 2010-05-27 Cymer, Inc. Laser produced plasma EUV light source
US20050279946A1 (en) * 2003-04-08 2005-12-22 Cymer, Inc. Systems and methods for deflecting plasma-generated ions to prevent the ions from reaching an internal component of an EUV light source
US20080179548A1 (en) * 2003-04-08 2008-07-31 Cymer, Inc. Laser produced plasma EUV light source
US7671349B2 (en) 2003-04-08 2010-03-02 Cymer, Inc. Laser produced plasma EUV light source
US8035092B2 (en) 2003-04-08 2011-10-11 Cymer, Inc. Laser produced plasma EUV light source
EP1557844A2 (en) * 2003-10-20 2005-07-27 ASML Netherlands B.V. Use of a top layer on a mirror for use in a lithographic apparatus, mirror for use in a lithographic apparatus, lithographic apparatus comprising such a mirror and device manufacturing method
US20050111080A1 (en) * 2003-10-20 2005-05-26 Asml Netherlands B.V. Mirror for use in a lithographic apparatus, lithographic apparatus, device manufacturing method, and device manufactured thereby
US7592610B2 (en) 2003-10-20 2009-09-22 Asml Netherlands B.V. Mirror for use in a lithographic apparatus, lithographic apparatus, device manufacturing method, and device manufactured thereby
EP1557844A3 (en) * 2003-10-20 2006-03-01 ASML Netherlands B.V. Use of a top layer on a mirror for use in a lithographic apparatus, mirror for use in a lithographic apparatus, lithographic apparatus comprising such a mirror and device manufacturing method
US20060249699A1 (en) * 2004-03-10 2006-11-09 Cymer, Inc. Alternative fuels for EUV light source
US20050269529A1 (en) * 2004-03-10 2005-12-08 Cymer, Inc. Systems and methods for reducing the influence of plasma-generated debris on the internal components of an EUV light source
US20070187627A1 (en) * 2004-03-10 2007-08-16 Cymer, Inc. Systems and methods for reducing the influence of plasma-generated debris on the internal components of an EUV light source
US7732793B2 (en) 2004-03-10 2010-06-08 Cymer, Inc. Systems and methods for reducing the influence of plasma-generated debris on the internal components of an EUV light source
US20050286599A1 (en) * 2004-06-29 2005-12-29 Rafac Robert J Method and apparatus for gas discharge laser output light coherency reduction
US8143790B2 (en) 2004-07-09 2012-03-27 Energetiq Technology, Inc. Method for inductively-driven plasma light source
US20080042591A1 (en) * 2004-07-09 2008-02-21 Energetiq Technology Inc. Inductively-Driven Plasma Light Source
US20060017387A1 (en) * 2004-07-09 2006-01-26 Energetiq Technology Inc. Inductively-driven plasma light source
US7948185B2 (en) 2004-07-09 2011-05-24 Energetiq Technology Inc. Inductively-driven plasma light source
US7307375B2 (en) 2004-07-09 2007-12-11 Energetiq Technology Inc. Inductively-driven plasma light source
US20060006345A1 (en) * 2004-07-09 2006-01-12 Energetig Technology Inc. Inductively-driven light source for lithography
US7199384B2 (en) 2004-07-09 2007-04-03 Energetiq Technology Inc. Inductively-driven light source for lithography
US7183717B2 (en) 2004-07-09 2007-02-27 Energetiq Technology Inc. Inductively-driven light source for microscopy
US20060006808A1 (en) * 2004-07-09 2006-01-12 Energetiq Technology Inc. Inductively-driven light source for microscopy
US20060006775A1 (en) * 2004-07-09 2006-01-12 Energetiq Technology Inc. Inductively-driven plasma light source
US20060097203A1 (en) * 2004-11-01 2006-05-11 Cymer, Inc. Systems and methods for cleaning a chamber window of an EUV light source
US20060219957A1 (en) * 2004-11-01 2006-10-05 Cymer, Inc. Laser produced plasma EUV light source
US20060289808A1 (en) * 2005-06-27 2006-12-28 Cymer, Inc. Euv light source collector erosion mitigation
US7394083B2 (en) 2005-07-08 2008-07-01 Cymer, Inc. Systems and methods for EUV light source metrology
US7569791B2 (en) 2005-09-30 2009-08-04 Energetiq Technology, Inc. Inductively-driven plasma light source
US20070075053A1 (en) * 2005-09-30 2007-04-05 Energetiq Technology, Inc. Inductively-driven plasma light source
US8227771B2 (en) * 2007-07-23 2012-07-24 Asml Netherlands B.V. Debris prevention system and lithographic apparatus
US20090027637A1 (en) * 2007-07-23 2009-01-29 Asml Netherlands B.V. Debris prevention system and lithographic apparatus
US8198615B2 (en) 2007-08-31 2012-06-12 Cymer, Inc. Gas management system for a laser-produced-plasma EUV light source
US20100140514A1 (en) * 2007-08-31 2010-06-10 Cymer, Inc. Gas management system for a laser-produced-plasma EUV light source
US20090057567A1 (en) * 2007-08-31 2009-03-05 Cymer, Inc. Gas management system for a laser-produced-plasma EUV light source
US7655925B2 (en) 2007-08-31 2010-02-02 Cymer, Inc. Gas management system for a laser-produced-plasma EUV light source
US20090154642A1 (en) * 2007-12-14 2009-06-18 Cymer, Inc. System managing gas flow between chambers of an extreme ultraviolet (EUV) photolithography apparatus
US7812329B2 (en) 2007-12-14 2010-10-12 Cymer, Inc. System managing gas flow between chambers of an extreme ultraviolet (EUV) photolithography apparatus
US20100032590A1 (en) * 2008-08-06 2010-02-11 Cymer, Inc. Debris protection system having a magnetic field for an EUV light source
US8519366B2 (en) 2008-08-06 2013-08-27 Cymer, Inc. Debris protection system having a magnetic field for an EUV light source
US20120146511A1 (en) * 2009-09-01 2012-06-14 Ihi Corporation Plasma light source
US8648536B2 (en) * 2009-09-01 2014-02-11 Ihi Corporation Plasma light source
US9000402B2 (en) * 2009-09-01 2015-04-07 Ihi Corporation LPP EUV light source and method for producing the same
US20120145930A1 (en) * 2009-09-01 2012-06-14 Tokyo Institute Of Technology Llp euv light source and method for producing the same
US8629417B2 (en) 2010-02-22 2014-01-14 Gigaphoton Inc. Extreme ultraviolet light generation apparatus
US8440988B2 (en) 2010-12-09 2013-05-14 Plex Llc Pulsed discharge extreme ultraviolet source with magnetic shield
US9357626B2 (en) 2012-06-12 2016-05-31 Asml Netherlands B.V. Photon source, metrology apparatus, lithographic system and device manufacturing method
US8921814B2 (en) 2012-06-12 2014-12-30 Asml Netherlands B.V. Photon source, metrology apparatus, lithographic system and device manufacturing method

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